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brymen-dmm: unbreak BM85x communication by pulsing RTS after COM port open
[libsigrok.git] / src / hardware / brymen-dmm / api.c
1 /*
2  * This file is part of the libsigrok project.
3  *
4  * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
5  *
6  * This program is free software: you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation, either version 3 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19
20 #include <config.h>
21 #include "protocol.h"
22
23 static const uint32_t scanopts[] = {
24         SR_CONF_CONN,
25         SR_CONF_SERIALCOMM,
26 };
27
28 static const uint32_t drvopts[] = {
29         SR_CONF_MULTIMETER,
30 };
31
32 static const uint32_t devopts[] = {
33         SR_CONF_CONTINUOUS,
34         SR_CONF_LIMIT_SAMPLES | SR_CONF_SET,
35         SR_CONF_LIMIT_MSEC | SR_CONF_SET,
36 };
37
38 static GSList *brymen_scan(struct sr_dev_driver *di, const char *conn,
39         const char *serialcomm)
40 {
41         struct sr_dev_inst *sdi;
42         struct dev_context *devc;
43         struct sr_serial_dev_inst *serial;
44         int rts_toggle_delay_us;
45         GSList *devices;
46         int ret;
47         uint8_t buf[128];
48         size_t len;
49
50         serial = sr_serial_dev_inst_new(conn, serialcomm);
51
52         if (serial_open(serial, SERIAL_RDWR) != SR_OK)
53                 return NULL;
54         /*
55          * The device requires an RTS *pulse* before communication.
56          * The vendor's documentation recommends the following sequence:
57          * Open the COM port, wait for 100ms, set RTS=1, wait for 100ms,
58          * set RTS=0, wait for 100ms, set RTS=1, configure bitrate and
59          * frame format, transmit request data, receive response data.
60          */
61         rts_toggle_delay_us = 100 * 1000; /* 100ms */
62         g_usleep(rts_toggle_delay_us);
63         serial_set_handshake(serial, 1, -1);
64         g_usleep(rts_toggle_delay_us);
65         serial_set_handshake(serial, 0, -1);
66         g_usleep(rts_toggle_delay_us);
67         serial_set_handshake(serial, 1, -1);
68         g_usleep(rts_toggle_delay_us);
69
70         sr_info("Probing port %s.", conn);
71
72         devices = NULL;
73
74         /* Request reading */
75         if ((ret = brymen_packet_request(serial)) < 0) {
76                 sr_err("Unable to send command: %d.", ret);
77                 goto scan_cleanup;
78         }
79
80         len = sizeof(buf);
81         ret = brymen_stream_detect(serial, buf, &len, brymen_packet_length,
82                              brymen_packet_is_valid, 1000, 9600);
83         if (ret != SR_OK)
84                 goto scan_cleanup;
85
86         sr_info("Found device on port %s.", conn);
87
88         sdi = g_malloc0(sizeof(struct sr_dev_inst));
89         sdi->status = SR_ST_INACTIVE;
90         sdi->vendor = g_strdup("Brymen");
91         sdi->model = g_strdup("BM85x");
92         devc = g_malloc0(sizeof(struct dev_context));
93         sr_sw_limits_init(&devc->sw_limits);
94         sdi->inst_type = SR_INST_SERIAL;
95         sdi->conn = serial;
96         sdi->priv = devc;
97         sr_channel_new(sdi, 0, SR_CHANNEL_ANALOG, TRUE, "P1");
98         devices = g_slist_append(devices, sdi);
99
100 scan_cleanup:
101         serial_close(serial);
102
103         return std_scan_complete(di, devices);
104 }
105
106 static GSList *scan(struct sr_dev_driver *di, GSList *options)
107 {
108         struct sr_config *src;
109         GSList *devices, *l;
110         const char *conn, *serialcomm;
111
112         devices = NULL;
113
114         conn = serialcomm = NULL;
115         for (l = options; l; l = l->next) {
116                 src = l->data;
117                 switch (src->key) {
118                 case SR_CONF_CONN:
119                         conn = g_variant_get_string(src->data, NULL);
120                         break;
121                 case SR_CONF_SERIALCOMM:
122                         serialcomm = g_variant_get_string(src->data, NULL);
123                         break;
124                 }
125         }
126         if (!conn)
127                 return NULL;
128
129         if (serialcomm)
130                 devices = brymen_scan(di, conn, serialcomm);
131         else
132                 devices = brymen_scan(di, conn, "9600/8n1/dtr=1/rts=1");
133
134         return devices;
135 }
136
137 static int config_set(uint32_t key, GVariant *data,
138         const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
139 {
140         struct dev_context *devc;
141
142         (void)cg;
143
144         devc = sdi->priv;
145
146         return sr_sw_limits_config_set(&devc->sw_limits, key, data);
147 }
148
149 static int config_list(uint32_t key, GVariant **data,
150         const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
151 {
152         return STD_CONFIG_LIST(key, data, sdi, cg, scanopts, drvopts, devopts);
153 }
154
155 static int dev_acquisition_start(const struct sr_dev_inst *sdi)
156 {
157         struct dev_context *devc;
158         struct sr_serial_dev_inst *serial;
159
160         devc = sdi->priv;
161
162         sr_sw_limits_acquisition_start(&devc->sw_limits);
163         std_session_send_df_header(sdi);
164
165         serial = sdi->conn;
166         serial_source_add(sdi->session, serial, G_IO_IN, 50,
167                         brymen_dmm_receive_data, (void *)sdi);
168
169         return SR_OK;
170 }
171
172 static struct sr_dev_driver brymen_bm857_driver_info = {
173         .name = "brymen-bm857",
174         .longname = "Brymen BM857",
175         .api_version = 1,
176         .init = std_init,
177         .cleanup = std_cleanup,
178         .scan = scan,
179         .dev_list = std_dev_list,
180         .dev_clear = std_dev_clear,
181         .config_get = NULL,
182         .config_set = config_set,
183         .config_list = config_list,
184         .dev_open = std_serial_dev_open,
185         .dev_close = std_serial_dev_close,
186         .dev_acquisition_start = dev_acquisition_start,
187         .dev_acquisition_stop = std_serial_dev_acquisition_stop,
188         .context = NULL,
189 };
190 SR_REGISTER_DEV_DRIVER(brymen_bm857_driver_info);